Referring to FIG. 1, the left atrial appendage (LAA) 2 is an anatomic feature of the human heart 4, and is a vestigial remainder of the embryo-stage left atrium. The LAA 2 is differently-sized in different patients, meaning that it may be trivial in some patients and relatively large in others. The LAA 2 is generally is positioned within the pericardial space of the heart. The LAA 2 is a sac-like feature that has an opening 6 connecting the interior space of the LAA 2 to the interior space of the left atrium 8. That opening 6 may be small compared with the interior of the LAA 2, which may cause blood to stagnate and then clot inside the LAA 2. Indeed, the LAA 2 is a major source of thrombi in patients with atrial fibrillation. These thrombi, when dislodged from the LAA 2, may cause stroke, which can debilitate or kill the patient.
The use of the same reference symbols in different figures indicates similar or identical items.